我的Thorfile：

class Db < Thor

  desc "show_Version","some description ..."
  def show_version # <= needs a database connection
    puts ActiveRecord::Migrator.current_version
  end

  private

  def connect_to_database # <= call this always when a task from this file is executed
    # connect here to database
  end

end

我可以在每个任务中编写“connect_to_database”方法,但这似乎不是很干.